Method for low pressure filtration of plasma from blood

Abstract

A method for carrying out separation of plasma from whole blood, in which whole blood is passed through a filtration membrane means of a material suitable for separating plasma from whole blood and having a pore size from 0.1 to 0.6 microns at positive pressure differential across the membrane in a range up to just below 50 mm Hg. This provides an increased flow as compared to the flow obtained with higher pressures.

What is claimed is: 
     
       1. A method of separating plasma from whole blood, comprising the step of: directing a flow of whole blood across one face of a filtration membrane means which is made of a material suitable for separating plasma from whole blood and having a pore size from 0.1 to 0.6 microns, said flow being at a flow velocity of from 5 to 1500 cm  /min and being at a depth sufficient for separating plasma from the flow of blood, and at the same time generating a positive pressure differential across said membrane up to just below 50 mm Hg. for forcing plasma through the membrane, and collecting the plasma separated by the membrane.   
     
     
       2. A method as claimed in claim 1 in which the step of generating a pressure differential across said membrane comprises generating a pressure in a range from about 8.5 mm Hg. to just below 50 mm Hg. 
     
     
       3. A method as claimed in claim 1 in which the pressure generating step comprises generating a pressure in a range of from about 20 to about 40 mm Hg. 
     
     
       4. A method as claimed in claim 1 in which said membrane means is a film type membrane. 
     
     
       5. A method as claimed in claim 1 in which said membrane means is a hollow fiber membrane. 
     
     
       6. A method as claimed in claim 1 in which said membrane means is a hollow fiber membrane of hydrophilic material.